Rhinocarcinosoma

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Rhinocarcinosoma
Temporal range: Late Silurian, 427.4–419.2  Ma
Rhinocarcinosoma.png
Fossil carapace and portions of the abdomen of R. vaningeni
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Arthropoda
Subphylum: Chelicerata
Order:† Eurypterida
Superfamily:† Carcinosomatoidea
Family:† Carcinosomatidae
Genus:† Rhinocarcinosoma
Novojilov, 1962
Type species
†Rhinocarcinosoma vaningeni
(Clarke & Ruedemann, 1912)
Species
  • †R. cicerops(Clarke, 1907)
  • †R. dosonensisBraddy, Selden & Doan Nhat, 2002
  • †R. vaningeni(Clarke & Ruedemann, 1912)
Synonyms
  • Eurypterus ? ciceropsClarke, 1907
  • Eusarcus ? cicerops(Clarke, 1907)
  • Eusarcus vaningeniClarke & Ruedemann, 1912

Rhinocarcinosoma is a genus of eurypterid, an extinct group of aquatic arthropods. Fossils of Rhinocarcinosoma have been discovered in deposits ranging of Late Silurian age in the United States, Canada and Vietnam. The genus contains three species, the American R. cicerops and R. vaningeni and the Vietnamese R. dosonensis. The generic name is derived from the related genus Carcinosoma , and the Greek ῥινός (rhinós, "nose"), referring to the unusual shovel-shaped protrusion on the front of the carapace (head plate) of Rhinocarcinosoma, its most distinctive feature.

Contents

Other than the protrusion, Rhinocarcinosoma was anatomically very similar to its close relative, Eusarcana , though it lacked the scorpion-like telson (the posteriormost division of the body) of that genus. Further distinguishing features include more slender appendages and slightly different ornamentation of scales. In terms of size, Rhinocarcinosoma was a medium-sized carcinosomatid eurypterid, with the largest species, R. vaningeni, reaching lengths of 39 centimetres (15.4 in).

In contrast to other carcinosomatids, Rhinocarcinosoma is not known only from marine settings, but also from deposits that were once lakes or rivers. It was adapted to a bottom-dwelling lifestyle, as either a burrowing or digging scavenger or top predator, feeding on other invertebrates and small fish.

Description

Reconstruction of R. dosonensis Rhinocarcinosoma dosonensis.png
Reconstruction of R. dosonensis

Rhinocarcinosoma was a medium-sized carcinosomatid eurypterid, with the largest species, R. vaningeni, reaching lengths of 39 centimetres (15.4 in) and the second largest, R. dosonensis, reaching lengths of 22 centimetres (8.7 in). [1] In terms of the outline of the body, with a broad abdomen and a nearly tubular postabdomen (tail), Rhinocarcinosoma was similar to the related genus Eusarcana . [2] [3] Its appendages, large and with spines, are also similar to those of Eusarcana, [3] though the more anterior (forwards) appendages of Rhinocarcinosoma were more slender than those of Eusarcana. [4] Although historically assumed to have had a scorpion-like telson (the posteriormost division of the body), like Eusarcana, [3] [2] more complete fossils of R. dosonensis revealed that this was not the case, although the telson did slightly curve upwards. [4] Like Eusarcana, Rhinocarcinosoma possessed an ornamentation of scales on its carapace (head plate), though the scales of Rhinocarcinosoma were smaller and more closely arranged. [3] The type A genital appendage (female reproductive organ) of Rhinocarcinosoma was broader and more rounded than that of Eusarcana. [4]

The most distinctive feature of Rhinocarcinosoma was the shovel-shaped protrusion developed from the most forward-facing portion of the carapace. [5] It is possible that the snout was used for digging purposes. [3] As of yet, this feature is only confidently known from R. vaningeni, given that the relevant portion of the carapace has not been preserved in adult fossils of R. dosonensis [4] and R. cicerops (which lacks known adult fossils altogether). [3]

All species of Rhinocarcinosoma also share certain other features of the carapace, including the carapace being more or less subtriangular in shape, with a width to length ratio of about 3:2, and the ocellar mound (the raised surface where the ocelli, smaller eyes, were located) being placed centrally and being the highest point of the carapace. [3] [4] The species R. cicerops shares the forward and prominent position of the ocelli with R. vaningeni, but only has a slight development of the snout compared to the others. [3] Its fossils are also the smallest of any species, at only 4 centimetres (1.6 in) in length, [1] but all known fossil specimens of R. cicerops are of immature individuals, meaning that it is possible that the adults were even more similar to R. vaningeni. [3] Although formal synonymisation has never been conducted, it is possible that R. cicerops were actually juvenile R. vaningeni. [3] [4]

History of research

Assortment of fossils, mainly carapaces, of immature R. cicerops Rhinocarcinosoma cicerops fossils.png
Assortment of fossils, mainly carapaces, of immature R. cicerops

Rhinocarcinosoma fossils were first found in the Illion Shale of New York State in the United States, and they were first described and discussed in detail in John Mason Clarke's and Rudolf Ruedemann's 1912 The Eurypterida of New York. [5] The earliest described species of Rhinocarcinosoma was R. cicerops, described by Clarke in 1907 as Eurypterus ? cicerops. The species was described based on a single carapace discovered in the Shawangunk grit at Otisville, New York, [3] of Llandovery-Ludlow age [1] (dating not entirely certain but likely only Late Silurian, i.e. Ludlow). [4] Though the specimen was immature, Clarke considered the fossil so unusual, in that the compound eyes were so developed and the ocellar mound was fully developed despite the specimen being immature, that he named a new species. [3]

Clarke and Ruedemann referred Clarke's species to the genus Eusarcus (now known as Eusarcana ) in 1912, designating it as Eusarcus (?) cicerops. Accompanying the reclassification were the assignment of several more fossils of varying sizes to the species. The reclassification to Eusarcus, although provisional, was based on the head and abdomen of E?. cicerops resembling species of that genus, in particular in the width of the body, the sub-triangular outline of the carapace and the oval shape and more or less marginal position of the eyes. [3]

The Eurypterida of New York figure 108-110.jpg
The Eurypterida of New York figure 111-115.jpg
Fossils of R. vaningeni, consisting of carapaces (left) and various segments as well as complete and partial appendages (right)

The species R. vaningeni was also described by Clarke and Ruedemann in The Eurypterida of New York, like R. cicerops designated as a species of Eusarcus (as Eusarcus vaningeni). Regarded by Clarke and Ruedemann as "very unexpected and peculiar" and "puzzling", E. vaningeni was described based on fossils from Oriskany Creek in Oneida County, New York, [3] of Ludlow age. [1] Although Clarke and Ruedemann considered E. vaningeni to be undoubtedly similar to Eusarcus scorpionis (the generic type species) in general, the position of the ocelli between the eyes and the large shovel-like projection in the front represented considerable differences from the type material. The snout also being developed in R. cicerops, though not to the same degree, as well as the position of the ocelli being similar, was noted by Clarke and Ruedemann as similarities between the two species. [3] E. vaningeni and E. cicerops were ultimately placed in their own genus, Rhinocarcinosoma, by Nestor Ivanovich Novozhilov in 1962, based on the placement of the eyes, the shape of the carapace and the protrusion at the front of the carapace. [4] The genus name derives from the related genus Carcinosoma and the Greek ῥινός (rhinós, "nose"). [6]

The holotype specimen of R. dosonensis was discovered in a quarry in 1989 on the Ngọc Xuyên hill on the Dô Son Peninsula in northern Vietnam, part of the Dô Son Formation. Initially believed to be the remains of a chasmataspidid, it was recognised as probably being a carcinosomatid fossil in 1993. [4] Further fossils of R. dosonensis were discovered in November 1993 [2] at two quarries on the Ngọc Xuyên hill. [4] Though no new species was named at the time, the eurypterid fossils could quickly be identified as belonging to Rhinocarcinosoma. [2] The new species R. dosonensis, named after the Dô Son Peninsula, was described in 2002 based on the Vietnamese fossils. Although the Vietnamese fossils did not preserve the diagnostic feature of Rhinocarcinosoma, the shovel-shaped protrusion at the front of the carapace (although some juvenile specimens preserve a slight protrusion), they could be referred to Rhinocarcinosoma on account of the rounded type A genital appendage, the triangular shape of the carapace and the slender shape of the more anterior appendages.

The fossil material of R. dosonensis is the most complete of any species of Rhinocarcinosoma. The new species R. dosonensis was created for the fossils given that they differed from both R. cicerops and R. vaningeni. A juvenile specimen of R. dosonensis, of about the same size as specimens of R. cicerops, has a markedly different carapace shape and whereas the metastoma (a plate on the underside of the abdomen) of R. vaningeni expands in size anteriorly, it stays about the same size in R. dosonensis. [4]

Though Rhinocarcinosoma is a very rare genus of eurypterids, [2] [3] [4] [5] specimens have also been found elsewhere, though they have not been assigned to any particular species. In 1985, Brian Jones and Erik N. Kjellesvig-Waering referred a poorly preserved part of a prosoma recovered in the Leopold Formation on Somerset Island in Canada to Rhinocarcinosoma sp. indet., [7] an assignment which has been maintained as correct in later research. [8] In 1992, Samuel J. Ciurca reported a Rhinocarcinosoma specimen, a carapace, from the McKenzie Formation just east of Lock Haven, Pennsylvania. [5]

Classification

Reconstruction of Eusarcana, a close relative of Rhinocarcinosoma The Eurypterida of New York plate 27.jpg
Reconstruction of Eusarcana , a close relative of Rhinocarcinosoma

Rhinocarcinosoma is classified as part of the family Carcinosomatidae, a family within the superfamily Carcinosomatoidea, alongside the genera Carcinosoma, Eocarcinosoma , Eusarcana [9] and possibly Holmipterus . [10] The first cladogram below is adapted from a larger cladogram (simplified to only display the Carcinosomatoidea) in a 2007 study by eurypterid researcher O. Erik Tetlie, which was in turn based on results from various phylogenetic analyses on eurypterids conducted between 2004 and 2007. [11] The second cladogram below is simplified from a study by Lamsdell et al. (2015). [10]

Palaeoecology

Size of the three species of Rhinocarcinosoma compared to a human hand Rhinocarcinosoma Scale.svg
Size of the three species of Rhinocarcinosoma compared to a human hand

Carcinosomatid eurypterids such as Rhinocarcinosoma were among the most marine eurypterids, [2] known from deposits that were once reefs, some in lagoonal settings, [5] and deeper waters. [12] In contrast to other carcinosomatids, Rhinocarcinosoma fossils are also known from non-marine environments, such as fluvial (river) and lacustrine (lake) settings. [2] The shovel-like development in the front of the carapace of Rhinocarcinosoma suggests a "mud-grubbing" [2] [3] and bottom-dwelling [2] lifestyle. More evidence for Rhinocarcinosoma being a bottom-dwelling genus comes in the form of its swimming paddles being reduced in size compared to those of its relatives, such as Carcinosoma. It is likely that Rhinocarcinosoma was either a top predator, actively digging for prey or burrowing and lying in wait, or a scavenger, digging for scraps, in its environment. Given its size, it is possible that Rhinocarcinosoma fed on worms, other arthropods, lingulids and small fish. Rhinocarcinosoma would most likely have fed through using its spined forward-facing appendages to push food into its mouth. [2]

The deposits at Otisville where R. cicerops have been discovered have also yielded other eurypterids, including Hughmilleria shawangunk, Nanahughmilleria clarkei, Ruedemannipterus stylonuroides, Erettopterus globiceps, Hardieopterus myops, Kiaeropterus otisius and Ctenopterus cestrotus. Also present were early jawed fish of the genus Vernonaspis . The environment in which R. cicerops lived was a marginal marine one (influenced by both salt and fresh water, such as a lagoon or delta). [13] The eurypterid-bearing deposits of Oneida County, which yielded the fossils of R. vaningeni, have also yielded other eurypterids, such as Eurypterus remipes. [3]

The Dô Son Formation, where R. dosonensis was discovered, very rarely preserves fossils meaning that dating the deposits is difficult. In what is presumably the lower member of the formation, fossils have been found of fishes Bothriolepis and Vietnamaspis and plants Colpodexylon and Lepidodendropsis . These fossils suggest a Givetian-Frasnian (Middle to Late Devonian) age. The presumed middle member of the formation, which has yielded the eurypterid fossils, also preserves brachiopod fossils ( Lingula ), bivalves ( Ptychoparia and Modiolopsis ) and fish remains. [4]

In addition to R. dosonensis, some fragmentary eurypterid fossils of the genus Hughmilleria are also known from the sites. [2] [4] Because the rock layers are relatively homogenous, researchers first assumed that the entire formation was Givetian-Frasnian in age. However, it is now believed that the eurypterid-bearing deposits are of Late Silurian age given that Rhinocarcinosoma is otherwise exclusively known from Late Silurian deposits (though it is not impossible for the genus to have survived unnoticed until the Late Devonian), fish remains from the same layer are similar to Late Silurian fish and palynological samples collected suggest a Late Silurian age. [4]

As the deposits have not been precisely dated, R. dosonensis and the fauna it co-occurred with have not been dated to a more precise timespan than 'Late Silurian'. [1] [9] [12] The sedimentology of the fossil deposits containing R. dosonensis suggest that the environment was a river delta in an otherwise semi-arid environment. [4]

See also

Related Research Articles

<span class="mw-page-title-main">Eurypterid</span> Order of arthropods (fossil)

Eurypterids, often informally called sea scorpions, are a group of extinct arthropods that form the order Eurypterida. The earliest known eurypterids date to the Darriwilian stage of the Ordovician period 467.3 million years ago. The group is likely to have appeared first either during the Early Ordovician or Late Cambrian period. With approximately 250 species, the Eurypterida is the most diverse Paleozoic chelicerate order. Following their appearance during the Ordovician, eurypterids became major components of marine faunas during the Silurian, from which the majority of eurypterid species have been described. The Silurian genus Eurypterus accounts for more than 90% of all known eurypterid specimens. Though the group continued to diversify during the subsequent Devonian period, the eurypterids were heavily affected by the Late Devonian extinction event. They declined in numbers and diversity until becoming extinct during the Permian–Triassic extinction event 251.9 million years ago.

<i>Eurypterus</i> Extinct genus of sea scorpions

Eurypterus is an extinct genus of eurypterid, a group of organisms commonly called "sea scorpions". The genus lived during the Silurian period, from around 432 to 418 million years ago. Eurypterus is by far the most well-studied and well-known eurypterid. Eurypterus fossil specimens probably represent more than 95% of all known eurypterid specimens.

<i>Hibbertopterus</i> Extinct genus of arthropods

Hibbertopterus is a genus of eurypterid, a group of extinct aquatic arthropods. Fossils of Hibbertopterus have been discovered in deposits ranging from the Devonian period in Belgium, Scotland and the United States to the Carboniferous period in Scotland, Ireland, the Czech Republic and South Africa. The type species, H. scouleri, was first named as a species of the significantly different Eurypterus by Samuel Hibbert in 1836. The generic name Hibbertopterus, coined more than a century later, combines his name and the Greek word πτερόν (pteron) meaning "wing".

<i>Slimonia</i> Extinct genus of arthropods

Slimonia is a genus of eurypterid, an extinct group of aquatic arthropods. Fossils of Slimonia have been discovered in deposits of Silurian age in South America and Europe. Classified as part of the family Slimonidae alongside the related Salteropterus, the genus contains three valid species, S. acuminata from Lesmahagow, Scotland, S. boliviana from Cochabamba, Bolivia and S. dubia from the Pentland Hills of Scotland and one dubious species, S. stylops, from Herefordshire, England. The generic name is derived from and honors Robert Slimon, a fossil collector and surgeon from Lesmahagow.

<i>Carcinosoma</i> Extinct genus of arthropods

Carcinosoma is a genus of eurypterid, an extinct group of aquatic arthropods. Fossils of Carcinosoma are restricted to deposits of late Silurian age. Classified as part of the family Carcinosomatidae, which the genus lends its name to, Carcinosoma contains seven species from North America and Great Britain.

<i>Hughmilleria</i> Genus of extinct arthropods

Hughmilleria is a genus of eurypterid, an extinct group of aquatic arthropods. Fossils of Hughmilleria have been discovered in deposits of the Silurian age in China and the United States. Classified as part of the basal family Hughmilleriidae, the genus contains three species, H. shawangunk from the eastern United States, H. socialis from Pittsford, New York, and H. wangi from Hunan, China. The genus is named in honor of the Scottish geologist Hugh Miller.

<span class="mw-page-title-main">Chasmataspidida</span> Order of arthropods

Chasmataspidids, sometime referred to as chasmataspids, are a group of extinct chelicerate arthropods that form the order Chasmataspidida. Chasmataspidids are probably related to horseshoe crabs (Xiphosura) and/or sea scorpions (Eurypterida), with more recent studies suggest that they form a clade (Dekatriata) with Eurypterida and Arachnida. Chasmataspidids are known sporadically in the fossil record through to the mid-Devonian, with possible evidence suggesting that they were also present during the late Cambrian. Chasmataspidids are most easily recognised by having an opisthosoma divided into a wide forepart (preabdomen) and a narrow hind part (postabdomen) each comprising 4 and 9 segments respectively. There is some debate about whether they form a natural group.

<i>Drepanopterus</i> Extinct genus of sea scorpions

Drepanopterus is an extinct genus of eurypterid and the only member of the family Drepanopteridae within the Mycteropoidea superfamily. There are currently three species assigned to the genus. The genus has historically included more species, with nine species having been associated with the genus Drepanopterus. Five of these have since been proven to be synonyms of pre-existing species, assigned to their own genera, or found to be based on insubstantial fossil data. The holotype of one species proved to be a lithic clast.

<i>Pittsfordipterus</i> Genus of arthropods (fossil)

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<i>Stylonurella</i> Extinct genus of arthropods

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<i>Eocarcinosoma</i> Extinct genus of arthropods

Eocarcinosoma is a genus of eurypterid, an extinct group of aquatic arthropods. The type and only species of Eocarcinosoma, E. batrachophthalmus, is known from deposits of Late Ordovician age in the United States. The generic name is derived from the related genus Carcinosoma, and the Greek eós meaning 'dawn', referring to the earlier age of the genus compared to other carcinosomatid eurypterids.

<i>Echinognathus</i> Extinct genus of arthropods

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<i>Parahughmilleria</i> Extinct genus of arthropods

Parahughmilleria is a genus of eurypterid, an extinct group of aquatic arthropods. Fossils of Parahughmilleria have been discovered in deposits of the Devonian and Silurian age in the United States, Canada, Russia, Germany, Luxembourg and Great Britain, and have been referred to several different species. The first fossils of Parahughmilleria, discovered in the Shawangunk Mountains in 1907, were initially assigned to Eurypterus. It would not be until 54 years later when Parahughmilleria would be described.

<span class="mw-page-title-main">Carcinosomatidae</span> Extinct family of arthropods

Carcinosomatidae is a family of eurypterids, an extinct group of aquatic arthropods. They were members of the superfamily Carcinosomatoidea, also named after Carcinosoma. Fossils of carcinosomatids have been found in North America, Europe and Asia, the family possibly having achieved a worldwide distribution, and range in age from the Late Ordovician to the Early Devonian. They were among the most marine eurypterids, known almost entirely from marine environments.

<span class="mw-page-title-main">Pterygotioidea</span> Extinct superfamily of eurypterids

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<span class="mw-page-title-main">Adelophthalmidae</span> Family of eurypterids

Adelophthalmidae is a family of eurypterids, an extinct group of aquatic arthropods. Adelophthalmidae is the only family classified as part of the superfamily Adelophthalmoidea, which in turn is classified within the infraorder Diploperculata in the suborder Eurypterina.

<i>Eusarcana</i> Extinct genus of sea scorpions

Eusarcana is a genus of eurypterid, an extinct group of aquatic arthropods. Fossils of Eusarcana have been discovered in deposits ranging in age from the Early Silurian to the Early Devonian. Classified as part of the family Carcinosomatidae, the genus contains three species, E. acrocephalus, E. obesus and E. scorpionis, from the Silurian-Devonian of Scotland, the Czech Republic and the United States respectively.

<span class="mw-page-title-main">Hughmilleriidae</span> Extinct family of eurypterids

Hughmilleriidae is a family of eurypterids, an extinct group of aquatic arthropods. The hughmilleriids were the most basal members of the superfamily Pterygotioidea, in contrast with the more derived families Pterygotidae and Slimonidae. Despite their classification as pterygotioids, the hughmilleriids possessed several characteristics shared with other eurypterid groups, such as the lanceolate telson.

<i>Eysyslopterus</i> Extinct genus of arthropods

Eysyslopterus is a genus of eurypterid, an extinct group of aquatic arthropods. Eysyslopterus is classified as part of the family Adelophthalmidae, the only clade within the derived ("advanced") Adelophthalmoidea superfamily of eurypterids. One fossil of the single and type species, E. patteni, has been discovered in deposits of the Late Silurian period in Saaremaa, Estonia. The genus is named after Eysysla, the Viking name for Saaremaa, and opterus, a traditional suffix for the eurypterid genera, meaning "wing". The species name honors William Patten, an American biologist and zoologist who discovered the only known fossil of Eysyslopterus.

<span class="mw-page-title-main">Timeline of eurypterid research</span>

This timeline of eurypterid research is a chronologically ordered list of important fossil discoveries, controversies of interpretation, and taxonomic revisions of eurypterids, a group of extinct aquatic arthropods closely related to modern arachnids and horseshoe crabs that lived during the Paleozoic Era.

References

  1. 1 2 3 4 5 Lamsdell, James C.; Braddy, Simon J. (2009). "Cope's rule and Romer's theory: patterns of diversity and gigantism in eurypterids and Palaeozoic vertebrates". Biology Letters. 6 (2): 265–9. doi:10.1098/rsbl.2009.0700. PMC   2865068 . PMID   19828493. Supplemental material.
  2. 1 2 3 4 5 6 7 8 9 10 11 Thanh, Tống Duy; Janvier, P.; Truong, Đoàn Nhật; Braddy, Simon (1994). "New vertebrate remains associated with Eurypterids from the Devonian Do Son Formation Vietnam". Journal of Geology. 3–4: 1–11.
  3. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 Clarke, John M.; Ruedemann, Rudolf (1912). The Eurypterida of New York. University of California Libraries. ISBN   978-1125460221.
  4. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 Braddy, Simon J.; Selden, Paul A.; Truong, Doan Nhat (2002). "A New Carcinosomatid Eurypterid From The Upper Silurian Of Northern Vietnam". Palaeontology. 45 (5): 897–915. Bibcode:2002Palgy..45..897B. doi:10.1111/1475-4983.00267. hdl: 1808/8358 . ISSN   1475-4983. S2CID   129450304.
  5. 1 2 3 4 5 Ciurca, Samuel J. (1992). "New occurrences of Silurian eurypterids (Carcinosomatidae) in Pennsylvania, Ohio and New York". The Paleontological Society Special Publications. 6: 57. doi: 10.1017/S2475262200006171 . ISSN   2475-2622.
  6. ↑ Meaning of rhino- at www.dictionary.com. Retrieved 27 July 2021.
  7. ↑ Jones, Brian; Kjellesvig-Waering, Erik N. (1985). "Upper Silurian Eurypterids from the Leopold Formation, Somerset Island, Arctic Canada". Journal of Paleontology. 59 (2): 411–417. ISSN   0022-3360. JSTOR   1305035.
  8. ↑ Braddy, Simon J.; Dunlop, Jason A. (2000). "Early Devonian eurypterids from the Northwest Territories of Arctic Canada". Canadian Journal of Earth Sciences. 37 (8): 1167–1175. doi:10.1139/e00-023. ISSN   0008-4077.
  9. 1 2 Dunlop, J. A.; Penney, D.; Jekel, D. (2015). "A summary list of fossil spiders and their relatives (version 16.0)" (PDF). World Spider Catalog.
  10. 1 2 Lamsdell, James C.; Briggs, Derek E. G.; Liu, Huaibao; Witzke, Brian J.; McKay, Robert M. (September 1, 2015). "The oldest described eurypterid: a giant Middle Ordovician (Darriwilian) megalograptid from the Winneshiek Lagerstätte of Iowa". BMC Evolutionary Biology . 15 (1): 169. Bibcode:2015BMCEE..15..169L. doi: 10.1186/s12862-015-0443-9 . PMC   4556007 . PMID   26324341.
  11. ↑ Tetlie, O. Erik (2007). "Distribution and dispersal history of Eurypterida (Chelicerata)" (PDF). Palaeogeography, Palaeoclimatology, Palaeoecology . 252 (3–4): 557–574. Bibcode:2007PPP...252..557T. doi:10.1016/j.palaeo.2007.05.011. Archived from the original (PDF) on 2011-07-18.
  12. 1 2 Tetlie, O. Erik (2007-09-03). "Distribution and dispersal history of Eurypterida (Chelicerata)". Palaeogeography, Palaeoclimatology, Palaeoecology. 252 (3–4): 557–574. Bibcode:2007PPP...252..557T. doi:10.1016/j.palaeo.2007.05.011. ISSN   0031-0182.
  13. ↑ "Otisville eurypterids (Silurian to of the United States)". The Paleobiology Database. Retrieved 27 July 2021.
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